1. Field of the Invention
The present invention relates to an optical navigating apparatus, and a computer readable recoding media that can perform an optical navigating method, and particularly relates to an optical navigating apparatus, and a computer readable recoding media that can perform an optical navigating method, which can estimate a moving speed of the optical navigating apparatus and accordingly adjusts light emitting frequency.
2. Description of the Prior Art
A prior art optical navigating apparatus utilizes a light source to illuminate a surface to generate an image. Then, an image sensor is utilized to catch pictures in an image and the pictures are computed to compute a moving speed of the optical navigating apparatus to perform tracking.
Please refer to FIG. 1, which illustrates a prior art optical mouse 100. An optical mouse is one kind of the optical navigating apparatuses. As shown in FIG. 1, the optical mouse 100 includes a light source 101, a controller 103, a image sensor 105. The light source 101, the controller 103 and the image sensor 105 are provided on a single circuit board 107. The optical mouse further includes a battery 109 to provide power to the optical mouse 100. The light source 101 illuminates a surface 102 such as the surface which the mouse is put on, to form an image. The image sensor 105 catches the pictures in the image. The controller 103 computes the speed and the acceleration of the optical mouse 100 to perform tracking operation.
Please refer to FIG. 2, which illustrates a tracking operation of the optical mouse 100 shown in FIG. 1. As shown in FIG. 2, the optical mouse continuously catches pictures and continuously performs computing operations to compute speed and acceleration of the optical mouse 100. However, in such method the power consumption is huge since the light source 101 continuously illuminates the surface 102, the image sensor continuously catches the image and the controller 103 continuously performs computing operations. Particularly, the data computing amount and the power consumption significantly increase when the optical navigating apparatus moves in a high speed mode, since a higher frequency for illuminating, image catching and computing is needed corresponding to increased difficulty for the tracking operation. A modern electronic apparatus is getting smaller thus the size of the battery 109 is limited. The stored power correspondingly decreases, thus shortage issue of power endurance for the optical navigating apparatus such as the optical mouse is caused.